1. Field of the Invention
This invention generally relates to wireless communication systems. More particularly, the invention relates to a wireless digital Code Division Multiple Access (CDMA) communication system including a base station and a plurality of subscriber units which selectively allocates bandwidth upon demand by a subscriber unit or an entity desiring to establish a communication with a subscriber unit.
2. Description of the Related Art
The use of wireless technology by the telecommunication industry has increased dramatically as the capacity and reliability of wireless communication systems has improved. Once considered only to be a convenient method for sending voiced communications, digital wireless communications systems are now a necessity for providing transmission of all forms of communications including plain old telephony service (POTS), integrated services digital network (ISDN), variable bit rate (VBR) data service, wideband service, leased line service and packet data services. Although it has been technically feasible to transmit all of these types of services, the large amount of bandwidth required for high data rate communications has made many of these services uneconomical. As the number of subscribers requiring access to wireless digital communication systems has increased, the reliance on a wide bandwidth for each communication is no longer realistic.
The finite bandwidth allocated to wireless communications systems for public use has become increasingly valuable. Since it is unlikely that additional bandwidth to support user growth will be allocated for existing applications, many of the recent advances in telecommunication hardware and software have been directed toward increasing the transmission rate of data while utilizing a decreased amount of bandwidth.
Accordingly, there exists a need for a wireless digital communication system which supports the same high data rate services as conventional wired networks while utilizing the allocated bandwidth more efficiently.
The present invention is a CDMA wireless digital communication system which supports all types of voice and data communications while utilizing the minimum amount of bandwidth for the particular application. The system efficiently allocates ISDN bandwidth on demand by a subscriber. Upon initialization of the subscriber unit, the system establishes a channel and generates the necessary spreading codes to support the highest capacity channel desired by the subscriber unit. However, the system does not set aside portions of the communication bandwidth until actually required by the subscriber unit. Since the call setup is performed at the beginning of any call from that particular subscriber unit, including the assignment of spreading codes, a subscriber unit can quickly gain access to the portion of the spectrum that is required to support the particular application.
Accordingly, it is an object of the invention to provide a wireless digital spread spectrum communication system which supports a range of telephone services including POTS and ISDN while efficiently utilizing the spread spectrum bandwidth.
Other objects and advantages of the present invention will become apparent after reading the description of a presently preferred embodiment.